Synthesis of 4,5-diarylthiazole derivatives as blood platelet aggregation inhibitors

A number of 2-substituted 4,5-diphenylthiazoles were synthesized by the nucleophilic substitution of 2-methylsulfonyl-4,5-diphenylthiazole with various sodium alkoxides, amines, and carbanions of active methylene compounds. 2-Methylsulfonyl-4,5-diphenylthiazole was obtained by the potassium permanganate oxidation of 2-methylthio-4,5-diphenylthiazole in the presence of a phase-transfer catalyst. 2-Ethoxy-4,5-bis(4-methoxyphenyl) thiazole was prepared in a similar manner. 2-Ethynyl-4,5-diphenylthiazoles were synthesized by the palladium catalyst cross-coupling reaction of 2-iodo-4,5-diphenylthiazole with monosubstituted acetylenes. These compounds were tested for inhibitory activity against blood platelet aggregation in vitro. Among them, 2-alkoxy-, and 2-(4-methylpiperazin-1-yl)-4,5-diphenylthiazole were found to have potent inhibitory activity.     

Singularities explained: Response to Klein.

Klein [Klein, A. S. (2006). Separating transducer nonlinearities and multiplicative noise in contrast discrimination. Vision Research, 46, 4279-4293] questions the existence of intrinsic singularities in two-alternative force-choice (2AFC) Signal Detection Theory (SDT) models, suggesting that the singularities found in Katkov et al. [Katkov, M., Tsodyks, M., & Sagi, D. (2006a). Singularities in the inverse modeling of 2AFC contrast discrimination data. Vision Research, 46, 259-266; Katkov, M., Tsodyks, M., & Sagi, D. (2006b). Analysis of two-alternative force-choice Signal Detection Theory model. Journal of Mathematical Psychology, 50, 411-420] are due to discarding higher order terms in the Taylor expansion of d' and/or limited to steep psychometric functions. Here we provide some simple intuitive examples that illustrate the results described in Katkov et al. (2006a, 2006b). We show, for the constant noise model, that singularities exist when exact values of d' are computed and that the singularities are not limited to steep psychometric functions. In these cases the disambiguation of the different models requires millions of trials.     

Prophylactic use of chlorpromazine to improve survival of random skin flaps in pigs

On the basis of earlier success in rat studies, chlorpromazine was evaluated as a probable agent for improving survival of random skin flaps in pigs. The aim was to exclude the possibility that the effect of the chlorpromazine is species specific and to find out if it is dose dependent. One hundred and five dorsally-based 12×4 cm flaps were raised unilaterally on the backs of 15 pigs. The animals were divided into three groups using 15 mg/kg chlorpromazine, 7.5 mg/kg chlorpromazine, and a saline-treated control group. Flaps in the control group averaged 40.57±3.17% necrosis, while flaps in the 15 mg/kg and 7.5 mg/kg chlorpromazine-treated groups averaged 31.53±4.77% and 11.47±2.22% necrosis respectively. These results demonstrate dose dependent beneficial affects of chlorpromazine and the survival of random skin flaps in the pig. Although ideal dose levels are still to be determined, flap survival improved with the prophylactic use of chlorpromazine at the lower 7.5 mg/kg dosage.     

Genetic testing for hearing loss: different motivations for the same outcome

Autism is a complex genetic disorder. Chromosome 15 is of particular interest in this disorder, because of previous reports of individuals with autism with chromosomal abnormalities in the 15q11-q13 region. Transmission disequilibrium between polymorphisms in this region and autism has been also been reported in some, but not all studies. Recently, a novel maternally expressed gene, ATP10C, was characterized and mapped to the chromosome 15q11-q13 region, 200 kb distal to UBE3A. It encodes a putative aminophospholipid translocase likely to be involved in the asymmetric distribution of proteins in the cell membrane. Preferential maternal expression has been demonstrated in fibroblasts and brain. Because of its physical location and imprinting pattern, ATP10C was considered to be a candidate gene for chromosome 15-associated autism. In an effort to find the genes responsible for autism in this chromosomal region, 1.5 kb of the 5' flanking region, as well as the coding and splicing regions of ATP10C, were screened for sequence variants. Several polymorphic markers including five nonsynonymous SNPs were identified. To investigate transmission disequilibrium between ATP10C and autism, a family-based association study was conducted for 14 markers in 115 autism trios. No significant transmission disequilibrium was found, suggesting ATP10C is unlikely to contribute strongly to susceptibility to autism in these families. However, due to limited power to detect genes of modest effect, the possible functional role of the nonsynonymous SNPs and the functional implications of the SNPs identified from 5' flanking region and intron 2 splicing region may be evaluated in further studies.     

Variability of Stickler syndrome.

Stickler syndrome is a dominantly inherited disorder characterized by ocular and nonocular manifestations. The phenotype of the affected patients is known to be variable. Our study of 3 families and a review of the literature show that the variability is mostly interfamilial while in each family less variability is present. In one family all the patients had high myopia and most developed a retinal detachment at a young age. In the second family the major symptoms were cleft palate and characteristic facial changes in presence of mild ocular changes. In the third family, all patients had a marfanoid habitus, high myopia, and mental retardation. Interfamilial variability coupled with intrafamilial similarities in clinical manifestation may indicate that the so-called Stickler syndrome represents in fact a phenotype and not a single genetic entity.     

Mortality in bullous pemphigoid: A systematic review and meta‐analysis of standardized mortality ratios

There are inconsistent data on mortality rates in patients with bullous pemphigoid (BP). Trends in mortality in BP throughout the years are yet to be established. The aim of the present study was to study the mortality in BP patients relative to the general population and to estimate trends in standardized mortality over the past 30 years. We performed a systematic review and meta‐analysis of observational studies in Medline, Embase and Scopus (1823–2017). Reference lists of included studies were also searched for eligible studies. Quality of evidence was assessed using the Newcastle–Ottawa Scale (NOS). A meta‐analysis was performed using random‐effects models to estimate pooled standardized mortality ratios (SMR) with 95% confidence intervals (CI). Meta‐regression models were used to investigate the secular trends in SMR. Ten studies were included covering the period 1960–2015 (1736 patients, 746 deaths). Pooled all‐cause SMR was 3.6 (95% CI, 2.6–5.0). There was no trend in all‐cause SMR across the last three decades (regression coefficient 0.02 [change in logSMR/year]; 95% CI, 0.04–0.08; P = 0.545). In conclusion, there is a 3.6‐fold increased mortality among patients with BP as compared with the age‐matched general population. The excess mortality in BP has not changed significantly over the past 30 years.     

Changes in protein kinase C during vitellogenesis in the crayfish Cherax quadricarinatus--possible activation by methyl farnesoate

During ovarian maturation in the crayfish Cherax quadricarinatus, changes in ovarian protein kinase C (PKC) isoenzymes take place in parallel to yolk accumulation (as shown by immunoblot analysis). Significant changes were recorded in the amounts of specific isoenzymes and in their distribution between the cytosol and the membranes. Ovarian maturation was accompanied by the appearance of high- and low-molecular-weight immunoreactive PKC isoenzyme species. Among the isoenzymes tested, PKC alpha was the most clearly activated during ovarian maturation, as shown by significant translocation from the cytosol to the particulate fraction and the appearance of high-molecular-weight species. Moreover, a similar picture was obtained in the ovaries of intersex individuals upon induction of secondary vitellogenesis by androgenic gland ablation. Immunohistological staining showed PKC alpha to be localized mainly in the cytosol of premature oocytes, whereas in later maturation stages, it was concentrated around the nucleus in a vesicular structure and in the oocyte membrane. In secondary vitellogenic stages, PKC was localized in the plasma membrane and apparently in follicular cells. In addition, its activity was demonstrated by in vitro phosphorylation assays of a crayfish ovarian homogenate. Activation of total PKC phosphorylation of histone, an external substrate, was induced by phosphatidylserine plus 12-O-tetradecanoylphorbol-13-acetate (TPA) or methyl farnesoate. Both TPA and methyl farnesoate stimulated activation of PKC alpha in organ culture, causing its translocation from the cytosol to the membranes and inducing autophosphorylation of threonine residues. The changes in PKC isoenzymes during ovarian maturation in the crayfish suggest their involvement in this process as well as a possible regulatory role for methyl farnesoate through a direct effect on some PKC isoenzymes.     

The dentate gyrus in depression

Extensive preclinical research has been conducted in recent years to reveal the cell types, neuronal circuits and molecular and morphological changes implicated in the function of the dentate gyrus in depression. This was profoundly facilitated by the emergence of methods such as gene targeting, neuronal cell activity manipulation, including optogenetics and chemogenetics, and the development of novel RNA sequencing technology and powerful MRI imagers that were used in clinical studies. These advancements provided researchers with the precise skills needed to evaluate the changes in the dentate gyrus structure and cell function in rodent models as well as in brains of depressed and medicated patients. Here, we review these latest findings and discuss the existing gaps in our knowledge of the role of the dentate gyrus in depression and in mediating the response to antidepressant therapies.     

Attachment in infancy and personal space regulation in early adolescence

This study longitudinally assessed associations between secure and ambivalent attachment with mothers, fathers and professional caregivers in infancy, and personal space regulation and perceived interpersonal competence in 64 early adolescents (31 boys, 33 girls). Children classified as ambivalently attached to their mothers and/or professional caregivers in infancy displayed significantly larger permeability of personal space as compared with children classified as securely attached. Attachment classifications with fathers were not associated with personal space behavior at 12 years of age. Children who had an insecure attachment relationship with both the mother and the professional caregiver in infancy displayed smaller personal space boundaries, and tolerated larger intrusions into their personal space as compared with children who had two secure attachments in infancy. Finally, perceived interpersonal competence was positively correlated with personal space permeability.